The goal of this two part proposal is to determine the effectiveness of a new pharmacologic agent, ritanserin, in the treatment of women with cocaine abuse. Compared to men, women exhibit a more rapid course of cocaine addiction and do worse in treatment. In addition, they are underrepresented in drug abuse studies. Ritanserin, a selective 5-HT2 serotonin antagonist, has been shown to decrease cocaine use in rats, decrease alcohol intake and depression in humans, and has a good safety profile. Additionally, it appears to have no abuse potential. Study 1 will evaluate the effects of ritanserin on cocaine self- administration in both depressed and non-depressed women with cocaine abuse. This study is a four week, double-blind trial of 84 depressed and 84 non-depressed subjects randomized into ritanserin or placebo conditions. Outcome will be determined by urine drug screens, drug use diaries and changes in craving and depression measures. Study 2 will determine the effect of ritanserin on relapse to cocaine use in a six month, double-blind, placebo-controlled trial of 100 depressed and 100 non-depressed women with cocaine abuse. A standardized psychosocial treatment component emphasizing relapse prevention is included in Study 2. Outcome measures include drug screen urinalysis, drug use diaries and changes on craving, depression and relapse scales. Hypotheses to be tested are: (1) ritanserin will decrease both the self- administration of cocaine and relapse to cocaine in both depressed and non-depressed women with a greater effect in depressed women; (2) ritanserin will decrease craving for cocaine; (3) ritanserin will decrease the frequency of relapses to cocaine and the consequences of relapse; and (4) depressive signs and symptoms will be decreased in ritanserin groups as compared to placebo. This work will test the efficacy of a new pharmacologic agent, ritanserin, in the treatment of cocaine abuse. It will also expand upon the limited knowledge of women with cocaine abuse.